It is well known that universal joints, and in particular high angle double cardan universal joints, need lubrication over a prolonged period of high speed operation, without throwing the lubrication out due to centrifugal and other forces on the universal joint. This is discussed in U.S. Pat. Nos. 4,781,662 and 5,688,065, the disclosures of which are hereby incorporated by reference for their disclosures of universal joints, and in particular lubrication of universal joints.
Although universal joints are well known in the art, a problem persists in retaining lubricant in the joint for as long as possible. Typically, the joint is lubricated when new. After being placed in service, the joint may never be lubricated again. The joint is subjected to centrifugal forces in service, which tend to cause the lubricant to be thrown radially outward. The invention described herein is accordingly directed to retaining lubricant in the joint during operation.